Re: git: kernel - Add MONITOR/MWAIT support to the LWKT scheduler

From:

Matthew Dillon <dillon@xxxxxxxxxxxxxxxxxxxx>

Date:

Sun, 26 Dec 2010 11:53:41 -0800 (PST)

:This commit removes the RQF_IDLECHECK_WK_MASK check *before*
:the CLI instruction when MONITOR/MWAIT is unavailable, because
:of how C evaluates expressions. Some strange panic in vm_map_lookup()
:started annoying me after upgrading the kernel recently, and
:bisecting showed that this is the first commit with the problem.
:
:I'm running the kernel with the following change to see if it
:fixes the panic, which usually takes several hours to be triggered.
:
:Best Regards,
:YONETANI Tomokazu
Theoretically it shouldn't matter. All that happens is that the
splz() gets run while in CLI and then the WK_MASK check after that
prevents the idle thread from halting.
What's the strange panic in vm_map_lookup()? The changes might be
revealing other bugs which have been present for a longer period
of time rather than being bugs themselves.
In anycase, this week I will try to work through all the reported
bugs. I was able to reproduce the 'lockmgr: locking against myself'
bug using your grep --mmap test. I'll try to track that down in
what little time I have today. I will have a lot more time to
work on things this coming week.
-Matt